Open-source toolbox for photographic characterization of optical propagation.

An alternative method for characterizing optical propagation in waveguide structures based on scattered light imaging is presented and demonstrated for the spectral range of 450-980 nm. Propagation losses as low as 1.40 dB/cm are demonstrated in alumina spiral waveguides. AlGaAs-on-insulator waveguides are measured using a tunable laser and compared to cut-back measurements. On AlGaAs, a one-sigma uncertainty of 1.40 and 2.23 dB/cm for TE and TM polarizations is obtained for repetitions of measurements conducted on the same waveguide, highlighting the approach's reproducibility. An open-source toolbox is introduced, allowing for reliable processing of data and estimation of optical propagation losses.